TWENTY-FOURTH ANNUAL EASTERN FISH HEALTH WORKSHOP Royal Pavilion Resort, Atlantic Beach, NC MARCH 9-11, 1999 Infectious Salmon Anaemia Virus: Survival In Fresh And Seawater And Susceptibility To Iodine Disinfectants Laura L.Brown, Robyn M. MacQuarrie, Sandra A. Sperker National Research Council Canada, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, B3H 3Z1. Infectious Salmon Anaemia virus (ISAV) is the cause of ISA in salmonids, and is a serious problem in farmed fish in Norway, Scotland, and Canada. ISAV has been shown experimentally to be transmitted between fish in fresh water, and experimentally and clinically in seawater. Therefore, it is very important to examine the survival of the virus in these different environments. Iodophores are used as disinfectants in most freshwater salmonid hatcheries, yet nothing is known about the susceptibility of ISAV to these chemicals. To determine the survival of ISAV in fresh and seawater, a Canadian strain of the virus was exposed to fresh water and full-strength seawater for selected times (0 – 24 h). The virus was then inoculated onto a susceptible fish cell line, Salmon Head Kidney (SHK) cells. In order to determine the susceptibility of ISAV to iodophore, the virus was also exposed to selected disinfectant concentrations (0 – 1000 ppm active iodine) for 0 to 3 h. ISAV was inactivated (as measured by lack of infectivity on SHK cells) by an 8 h exposure to fresh water; shorter times did not inactivate the virus. In seawater, ISAV remained viable after an 8 h exposure. Qualitative observations suggested that the virulence of ISAV on the fish cell line decreased with increased time of exposure to fresh and seawater. Data on iodophore susceptibility will be discussed. These findings could be useful to the aquaculture industry in developing effective husbandry practices and regulatory standards in order to prevent infections due to ISAV. Return to 24th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page